Impact of drying and carrier composition on the moisture sorption behavior and quality properties of acacia honey powder

Acacia honey powder was prepared by spray drying and freeze drying using four carrier formulations based on maltodextrin, inulin, and fructooligosaccharides, and the experiment was arranged in a factorial design. Powders were characterized in terms of physicochemical properties (moisture content, water activity, color, solubility, and yield), thermal quality indicators (hydroxymethylfurfural and diastase number), and antioxidant-related parameters (total phenolic content, total flavonoid content, DPPH IC50, and ABTS radical-scavenging IC50, defined as the concentration required to inhibit 50% of radical activity). Moisture sorption isotherms were determined at 30°C and fitted using the Guggenheim – Anderson – de Boer (GAB) model. Shelf-life was estimated using a moisture-based accelerated shelf-life testing (ASLT) approach based on critical moisture content at 75% and 84% relative humidity. Spray drying produced powders with lower moisture content (2.01–2.69%) and water activity (0.29–0.31), and higher yield (up to 93.65%), compared with compared with freeze drying (6.48–8.85% and 0.45–0.52, respectively). Freeze-dried powders showed lower hydroxymethylfurfural levels (9.84–14.81 mg/kg) and higher diastase activity (up to 23.10) than spray-dried powders (16.13–18.84 mg/kg and up to 17.36, respectively). All treatments exhibited Type II isotherms, and the GAB model adequately described the data (R2 0.92–0.97), with monolayer moisture content ranging from 4.89 to 6.21 g H2O/100 g dry solid. Predicted shelf life at 75% relative humidity ranged from 235 to 614 d. Sensory acceptance scores ranged from 4 to 6 on a seven-point hedonic scale, indicating overall moderate acceptance.